Upholstered mobile task chairs and similar seating structures present a number of issues that must be confronted by the designer. A fundamental goal is, of course, to provide comfortable, ergonomically sound support to the seat occupant. While stable support is sought, it is also desirable to provide an upholstered seat bottom that permits enhanced flexibility and comfort in the support of the pelvis. The inventor has appreciated that still further advantage would be gained by providing resilient support in a seat bottom that can vary in a hyper-localized manner whereby the seat bottom can conform further and more accurately to a seat occupant's ergonomic needs. In upholstered seat design, a designer must further ensure that the seat pan underlying the upholstery and any underlying cushioning material permits breathability so that, for example, air trapped in the seat can escape when an occupant sits or changes position and air can enter the inner volume of the seat when the occupant leaves the seat.
It is further recognized that the prior art has taught largely that a seat back with lumbar support should move in relation to the seat bottom as a seat occupant reclines or leans forward. However, as disclosed herein, providing fixed angle pelvic support and positioning through a pelvic support and positioning member fixed in relation to the seat bottom is desirable in that doing so would maintain proper ergonomic positioning of a seat occupant's pelvis even during forward and rearward pivoting of the seat. Such fixed pelvic support and positioning has application not only to upholstered seats but also to seats with elastomeric material stretched over a framework as shown and described in the present inventor's co-pending application Ser. No. 14/133,502, filed Dec. 18, 2013, which is incorporated herein by reference.